The present invention relates to reciprocating plunger and piston-type pumps which are used, for example, in oilfield operations. In particular, the invention is related to an improved valve retainer for supporting a suction valve within the suction bore of the pump.
Plunger pumps for the oilfield industry generally include a plunger which is positioned in a plunger bore, a suction valve which is positioned in a suction bore and a discharge valve which is positioned in a discharge bore. In operation, the plunger is reciprocated in the plunger bore to alternately draw fluid into the pump through the suction valve and then force the fluid out of the pump through the discharge valve.
Prior art plunger pumps typically include a valve retainer for supporting and guiding the suction valve within the suction bore. Without this valve retainer, the suction valve and its corresponding parts would be free to rise into the path of the plunger and thereby damage the plunger or other parts of the pump. In some pumps the suction valve and the retainer comprise a single assembly. In other pumps, especially larger pumps, the valve retainer is installed separately from the suction valve.
In these later types of pumps, various means are used to mount the valve retainer within the plunger bore or the suction bore. One example of a prior art valve retainer is the “longhorn” style valve retainer. These valve retainers comprise a hub within which the stem of the suction valve is slidably received and two diametrically opposed “horns” which are rotated into corresponding grooves formed in the suction bore to thereby secure the hub in place. However, these grooves create stress concentrations within the suction bore which can reduce the serviceable life of the pump.